Task #14314: Add interface name/index APIs

This commit adds the following sets of interface name/index APIs:

Interface Identification APIs from RFC 3493:
  * lwip_if_nametoindex (COMPAT macro if_nametoindex)
  * lwip_if_indextoname (COMPAT macro if_indextoname)

netifapi:
  * netifapi_netif_name_to_index
  * netifapi_netif_index_to_name

netif:
  * netif_name_to_index
  * netif_index_to_name
  * netif_num_to_index
  * netif_index_to_num

src/include/lwip/if.h

@@ -0,0 +1,54 @@
+/**
+ * @file
+ * Interface Identification APIs from:
+ *              RFC 3493: Basic Socket Interface Extensions for IPv6
+ *                  Section 4: Interface Identification
+ */
+
+/*
+ * Copyright (c) 2017 Joel Cunningham <joel.cunningham@me.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Joel Cunningham <joel.cunningham@me.com>
+ *
+ */
+#ifndef LWIP_HDR_IF_H
+#define LWIP_HDR_IF_H
+
+#include "lwip/opt.h"
+
+#define IF_NAMESIZE 6 /* 2 chars, 3 nums, 1 \0 */
+
+char * lwip_if_indextoname(unsigned ifindex, char *ifname);
+unsigned int lwip_if_nametoindex(const char *ifname);
+
+#if LWIP_COMPAT_SOCKETS
+#define if_indextoname(ifindex, ifname)  lwip_if_indextoname(ifindex,ifname)
+#define if_nametoindex(ifname)           lwip_if_nametoindex(ifname)
+#endif /* LWIP_COMPAT_SOCKETS */
+
+#endif /* LWIP_HDR_IF_H */

src/include/lwip/netif.h

@@ -490,6 +490,14 @@ err_t netif_add_ip6_address(struct netif *netif, const ip6_addr_t *ip6addr, s8_t
 #define NETIF_SET_HWADDRHINT(netif, hint)
 #endif /* LWIP_NETIF_HWADDRHINT */
 
+/* @ingroup netif */
+u8_t netif_name_to_index(const char *name);
+char * netif_index_to_name(u8_t index, char *name);
+
+/* Interface indexes always start at 1 per RFC 3493, section 4, num starts at 0 */
+#define netif_num_to_index(netif)   ((netif)->num + 1)
+#define netif_index_to_num(index)   ((index) - 1)
+
 #ifdef __cplusplus
 }
 #endif

src/include/lwip/netifapi.h

@@ -40,6 +40,7 @@
 #include "lwip/netif.h"
 #include "lwip/dhcp.h"
 #include "lwip/autoip.h"
+#include "lwip/if.h"
 #include "lwip/priv/tcpip_priv.h"
 
 #ifdef __cplusplus
@@ -73,6 +74,14 @@ struct netifapi_msg {
       netifapi_void_fn voidfunc;
       netifapi_errt_fn errtfunc;
     } common;
+    struct {
+#if LWIP_MPU_COMPATIBLE
+      char name[IF_NAMESIZE];
+#else /* LWIP_MPU_COMPATIBLE */
+      char *name;
+#endif /* LWIP_MPU_COMPATIBLE */
+      u8_t index;
+    } ifs;
   } msg;
 };
 
@@ -92,6 +101,11 @@ err_t netifapi_netif_set_addr(struct netif *netif, const ip4_addr_t *ipaddr,
 err_t netifapi_netif_common(struct netif *netif, netifapi_void_fn voidfunc,
                             netifapi_errt_fn errtfunc);
 
+/** @ingroup netifapi_netif */
+err_t netifapi_netif_name_to_index(const char *name, u8_t *index);
+/** @ingroup netifapi_netif */
+err_t netifapi_netif_index_to_name(u8_t index, char *name);
+
 /** @ingroup netifapi_netif */
 #define netifapi_netif_remove(n)        netifapi_netif_common(n, netif_remove, NULL)
 /** @ingroup netifapi_netif */

src/include/posix/net/if.h

@@ -0,0 +1,33 @@
+/**
+ * @file
+ * This file is a posix wrapper for lwip/if.h.
+ */
+
+/*
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ */
+
+#include "lwip/if.h"